传感器类型
综述或非传感器论文
检测对象
葡萄糖(glucose)、ATP(adenosine triphosphate)、DNase I、Listeria monocytogenes、E. coli O157:H7、CD34+细胞;样品基质包括尿液、食品/肉样、水样、细胞悬液
检测原理
本文综述生物活性纸的通用检测原理:先将抗体、酶、适配体、噬菌体等识别元件通过物理吸附、生物墨水包埋、亲和结合或共价偶联固定于纤维素纸。样品经毛细作用进入纸面,被测物与识别元件发生特异性结合或催化反应,引起界面组成、构象或电子/光学状态变化。例如ATP结合适配体后使荧光-淬灭双链解离,产生荧光;酶催化底物显色用于比色或ELISA;噬菌体感染细菌后通过生物发光ATP检测反映病原菌活性。信号随被测物浓度增加而增强或减弱,最终由比色、荧光、ELISA或生物发光读出。
检测灵敏度
原文未报告LOD、线性范围、灵敏度斜率或R^2。
效应效果
本文未给出统一传感器的定量性能,而是比较不同固定化策略。物理吸附简单但易脱落、取向随机;生物活性墨水包埋因通用性和生物相容性最常用,可保护酶并提高热稳定性;共价偶联最稳定均匀,但步骤较多;CBD亲和固定可实现定向固定。文中提到链霉亲和素-生物素结合Kd约10^-15 mol/L,荧光适配体与氧化纤维素偶联效率约25%,固定化噬菌体感染性较游离噬菌体部分降低。应用覆盖纸基生物检测、防伪、食品/水质病原菌检测和抗菌纸,强调低成本、便携和现场检测潜力。
传感器的构成
- 基底:纤维素滤纸或微晶纤维素(MCC)膜,提供多孔毛细流动和生物分子固定化载体
- 表面活化层:高碘酸氧化醛基、环氧基、硅烷/溶胶-凝胶(sol–gel)或光反应纤维素,用于共价偶联
- 载体/墨水层:PNIPAM微凝胶、聚苯乙烯乳胶、磁性纤维素微球、TiO2纳米颗粒,用于包埋或携带生物分子
- 识别元件:抗体、酶(HRP、葡萄糖氧化酶)、噬菌体(T4)、DNA适配体、蛋白/合成聚合物,用于特异性识别
- 信号标记物:荧光基团/淬灭剂、辣根过氧化物酶(HRP)、生物发光ATP体系,用于产生可测信号
- 封闭层:Tween 20、牛血清白蛋白(BSA)、酪蛋白、脱脂奶,用于减少非特异吸附
中文摘要
研究具有主动识别能力、可执行分析功能的纸基传感器或功能材料正在快速发展,已有大量工作致力于在生物传感器水平上设计和制备生物活性纸,以检测潜在健康危害。制备生物活性纸的关键步骤是设计实验与操作流程,将抗体、酶、噬菌体、细胞、蛋白、合成聚合物和DNA适配体等生物分子固定化在适当制备的纸膜上。固定化方法可简要分为物理吸附、生物活性墨水包埋、生物亲和结合和共价化学键合固定化。每种方法各有特点。尽管每种生物分子-纸组合使用前都需优化,但生物活性墨水包埋法因通用性和生物相容性而最常用。目前生物活性纸有四种常见应用:纸基生物检测或用于样品前处理的纸基分析装置;包装与建筑行业的防伪与防篡改;食品与水质监测中的病原菌检测;以及利用抗菌纸灭活病原菌。本文综述并比较不同生物分子固定化技术,讨论当前趋势及现有、新兴和未来应用。
英文摘要
Research into paper-based sensors or functional materials that can perform analytical functions with active recognition capabilities is rapidly expanding, and significant research effort has been made into the design and fabrication of bioactive paper at the biosensor level to detect potential health hazards. A key step in the fabrication of bioactive paper is the design of the experimental and operational procedures for the immobilization of biomolecules such as antibodies, enzymes, phages, cells, proteins, synthetic polymers and DNA aptamers on a suitably prepared paper membrane. The immobilization methods are concisely categorized into physical absorption, bioactive ink entrapment, bioaffinity attachment and covalent chemical bonding immobilization. Each method has individual immobilization characteristics. Although every biomolecule-paper combination has to be optimized before use, the bioactive ink entrapment method is the most commonly used approach owing to its general applicability and biocompatibility. Currently, there are four common applications of bioactive paper: (1) paper-based bioassay or paper-based analytical devices for sample conditioning; (2) counterfeiting and countertempering in the packaging and construction industries; (3) pathogen detection for food and water quality monitoring; and (4) deactivation of pathogenic bacteria using antimicrobial paper. This article reviews and compares the different biomolecule immobilization techniques and discusses current trends. Current, emerging and future applications of bioactive paper are also discussed.